The solution addresses the tasks as follows:

1. Task 1 & 2 (Path Engineering): Task 1 (redundancy) is achieved via the (assumed) pre-configured mutual redistribution on R3 and R4. Task 2 (path selection) requires two actions:

• The metric weights command must be applied to all routers in EIGRP AS 10 (R3, R4, R5, R6) to ensure they can form adjacencies, as the K-values must match.
• To force the path R1->R3->R5->R6, the alternative path (R3->R4->R6) must be made less desirable. By increasing the delay on the e0/1 interfaces of R4 and R6, the EIGRP metric for that link becomes significantly higher (due to K3=255), forcing traffic over the R5 path.

1. Task 3 (Policy-Based Routing):

• Access-lists (R6_SOURCE_TRAFFIC, R2_SOURCE_TRAFFIC) are created on R3 to identify the specific source traffic.
• The pre-configured route-maps INTERNET1 and INTERNET2 are modified to use these ACLs and set the appropriate next-hop IP address for SP1 (209.165.200.229) and SP2 (209.165.200.237), respectively.

Cisco Systems, (2023). IP Routing: EIGRP Configuration Guide, Cisco IOS XE 17.

Section: "EIGRP Metrics" and "Configuring EIGRP Metric Weights". (Explains the metric weights command and the K-values [TOS] K1 K2 K3 K4 K5 syntax).

Section: "Configuring Interface Parameters". (Details the use of the delay command on an interface to influence EIGRP routing metrics, specified in tens of microseconds).

Cisco Systems, (2024). IP Switching: Cisco Express Forwarding Configuration Guide, Cisco IOS XE 17.

Section: "Configuring Policy-Based Routing". (Documents the standard procedure for PBR: creating an access-list to match traffic, configuring a route-map to match the ACL and set the next-hop, and applying the policy to an interface).

Cisco Systems, (2023). IP Routing: Protocol-Independent Configuration Guide, Cisco IOS XE 17.

Section: "Configuring Route-Maps". (Provides the syntax for creating and modifying route-map statements, including match ip address and set ip next-hop clauses).